Whisk together the minced lemongrass, garlic, shallot, condensed milk, annatto oil, black soy sauce, fish sauce, honey, and sesame oil in a bowl. Toss with the thinly sliced pork, cover, and marinate in the fridge for at least 2 hours.
Preheat your air fryer to 390°F (199°C). Cook the pork strips in a single layer for 6 to 8 minutes, flipping halfway through, until edges are crisped and caramelized.
Toast your baguettes at 350°F (175°C) for 3 to 5 minutes until paper-thin crisp, then slice open lengthwise.
Swipe a layer of Kewpie mayo evenly along both inside walls of the warm bread and on the other side a similar amount of Pate.
Layer the hot, sizzling lemongrass pork down the center of the baguette, pressing it gently into the crumb.
Slide the long cucumber spears and squeezed julienned Đồ Chua right alongside the meat, and top with a heavy handful of fresh cilantro sprigs. Close, cut diagonally, and serve immediately!